Asplenium tenerrimum Mett.

  • Authority

    Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.

  • Family

    Aspleniaceae

  • Scientific Name

    Asplenium tenerrimum Mett.

  • Description

    Species Description - Roots filamentous, fibrous, not proliferous; rhizomes suberect; rhizome scales black, clathrate, hair-like, 1.5–2 x 0.1–0.3 mm, entire; fronds clumped, 4–12 cm long; stipes atropurpureous at bases, lustrous, bicolorous above bases, but often blackish abaxially, 1–5 cm x 0.2–0.6 mm, 1/3 of frond length, glabrous, with greenish wings 0.1 mm wide; blades membranaceous, 3–5 x 2–3.5 cm, 3–4-pinnate, deltate, widest proximally, apices pinnatifid, not proliferous; rachises green or bicolorous for 1/2 their length, glabrous, with wings 0.1 mm wide; pinnae deltate, 3–5 pairs, 2–3 x 0.6–1.5 cm, 2–3-pinnate in larger fronds, ultimate segments linear or narrowly obovate, 0.5–0.8 mm wide, toothed near tips; veins simple, readily visible on both sides, but not ending in widened tips adaxially; indument abaxially of inconspicuous, tan, clavate hairs 0.1 mm long; sori 1 per ultimate segment, at bases of segments near vein fork; indusia 0.8–1.2 x 0.3–0.4 mm, margins erose; spores reniform.

  • Discussion

    Type. Venezuela. [Aragua:] near La Victoria, Fendler 368 (B; isotypes K, MO!, NY!, US!). Fig. 37J.

    Asplenium cuspidatum Lam. var. tenerrimum (Mett. ex Kuhn) C. V. Morton & Lellinger, Mem. New York Bot. Gard. 15: 29. 1966.

    Asplenium fournieri Kuhn ex E. Fourn., Bull. Soc. Bot. France 17: 237. 1870. Type. Nicaragua. Isla Omotepe [Omepepe], Le´vy 1159 (P!-2 sheets, photo NY!, UC!; isotypes B!, US!).

    This small, 3(–4)-pinnate species is similar in dissection and size to Asplenium delicatulum but differs in many details. Asplenium delicatulum has stipes green proximally, entire indusia, sori that are located midway on the ultimate segments, and shorter brown, retiform rhizome scales 0.5–0.8 mm long. It spreads by means of slender, stolon-like roots, which are absent in A. tenerrimum.